With increased plantings of hybrid winterfeed barley across the UK this season, growers are being urged to remember theimportance of protecting its large flag leaves.
According to Syngenta field technicalmanager Iain Anderson, as well as showing strong growth earlier in the season,due to hybrid vigour, HyvidoTM hybrid barley can have flag leaves upto three times bigger than a conventional winter barley.
Accordingly, they provide a large surfacefor capturing sunlight, he says. But many first-time growers may be unaware ofthis, he points out.
Traditionally with conventional winterbarley, lower leaves have tended to be the larger ones, explains Mr Anderson.However, Hyvido can look more like a wheat plant in its structure, with itslarge flag leaves. So theres a clear need to maximise the potential of thisleaf area.
Also, its important to remember there canbe at least two months between applying T2 flag leaf sprays to winter barley inMay and the crop being harvested. This is a key period for grain-filling.
For these reasons, we urge growers toconsider the long-lasting SDHI fungicide isopyrazam as part of their T2 in Hyvido for example, the isopyrazam + cyprodinil treatment, Cebara.
Not only does this help protectgreen leaf retention, but the disease spectrum it controls also fits wellwith the disease resistance ratings of a hybrid such as Hyvido Volume.
In a fungicide small plot trial on Hyvidolast year, Cebara applied at T1 and T2 delivered 12.2 t/ha, while comparisontreatments with Cebara applied only once at either T1 or T2 both resultedin yields 0.7-0.9 t/ha below this. This suggests T2 is at least as important asT1 in Hyvido yield protection, Mr Anderson adds.
So far this season, Mr Anderson says thedisease issues seen in winter barley crops, generally, have included brownrust, mildew and net blotch. However for T2, he says Ramularia risks must alsobe considered, and Rhynchosporium must not be ruled out.
With this in mind, we suggest includingBravo at T2 along with an isopyrazam-based treatment, he continues. Whatsalso important is to ensure that T2 fungicides are applied at the correct time.
Winter barley can grow rapidly at this timeof year. So monitor crops regularly, and dont be tempted to stretch theinterval between T1 and T2 even if it only seems a short time since the T1spray. Otherwise you could miss the optimum T2 growth stage and leave newgrowth unnecessarily exposed to disease, which then becomes difficult to cure.